216161399 has 4 divisors (see below), whose sum is σ = 217066080. Its totient is φ = 215256720.

The previous prime is 216161377. The next prime is 216161411. The reversal of 216161399 is 993161612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216161399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216161999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 451982 + ... + 452459.

It is an arithmetic number, because the mean of its divisors is an integer number (54266520).

Almost surely, 2^216161399 is an apocalyptic number.

216161399 is a deficient number, since it is larger than the sum of its proper divisors (904681).

216161399 is an equidigital number, since it uses as much as digits as its factorization.

216161399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 904680.

The product of its digits is 17496, while the sum is 38.

The square root of 216161399 is about 14702.4283368429. The cubic root of 216161399 is about 600.1494063117.

The spelling of 216161399 in words is "two hundred sixteen million, one hundred sixty-one thousand, three hundred ninety-nine".